Direct contact liquid air contaminant control system

ABSTRACT

The direct contact liquid air contaminant control system and method to revitalize air by removal of carbon dioxide and other trace gas contaminants use a direct contact air, liquid scrubber element and stripper element. The scrubber element has two rotor elements rotatably mounted in a housing first for centrifugal separation of an air flow and liquid absorbent mixture which liquid absorbent has absorbed carbon dioxide and trace gas contaminants. Then second for centrifugal separation of an air flow and acid water wash mixture which acid water wash has liquid absorbent and other contaminants. The processed air is then passed through a charcoal bed filter for further removal of contaminants. A rotary contact processor may also be used to reprocess contaminated liquid absorbent for reuse.

BACKGROUND OF THE INVENTION

[0001] This invention relates to an air environment control system thatrevitalizes air and more specifically to the apparatus that removescarbon dioxide and other trace gas contaminates as well as dehumidifiescabin air of aircraft and spacecraft. The new contaminant control systemuses rotary fluid contact machines to scrub cabin air and to reprocessliquid absorbent and water for reuse while extracting carbon dioxide andother contaminants.

[0002] Liquid amine (methanol amine water solutions) based carbondioxide and trace gas contaminant removal apparatus and processes forregeneration of air have been used in nuclear submarines for over fortyyears. Such systems are used to remove carbon dioxide for the breathingair and depend on gravity to process the liquid carbon amine or otherliquids and air mixture.

[0003] An example of a combustion gas carbon dioxide process andapparatus is disclosed in U.S. Pat. No. 5,318,758. This type of gasprocess involves towers and other structures that depend on gravity,blowers and pumps to process the gas. Such systems are not simple orcompact and do not work in reduced gravity environments such as onaircraft and spacecraft.

[0004] The use of alternative absorbent solutions has been disclosed inU.S. Pat. Nos. 4,285,918 and 3,632,519. These patents teach that watersolutions of 3-amino-1,2 propanediol and ω-aminomethyl alkyl sulfonehave improved performance for carbon dioxide removal in closedenvironments such as submarines. They address only the removal of carbondioxide whereas there are a number of other contaminants that must beremoved in these closed environments.

[0005] Centrifugal liquid and gas processors have been explored asdescribed in the article “The Centrifugal Mass Exchange Apparatus inAir-Conditioning System of Isolated, Inhabited Object and Its WorkControl”, by P. A. Barabash, et al, in Proceedings of the 4^(th)European Symposium on Space Environmental and Control Systems, Oct.21-24, 1991. The article postulates use of a centrifugal apparatus towork with an air-conditioning system in a closed habitat system such asan orbital space station. A single stage system is proposed that keepsair temperature and humidity parameters within limits. The single stagerotor does not anticipate a more staged air process system usingcontaminant absorbent fluids and acid wash to provide carbon dioxide andother contaminant removal from a cabin air environment.

[0006] As can be seen, there is a need for a simple, compact airregeneration system and method for use in aircraft and spacecraft.

SUMMARY OF THE INVENTION

[0007] An improved air contaminant control system and method accordingto the present invention comprises a carbon dioxide scrubber, a liquidabsorbent stripper, a charcoal filter, and supporting containers, pumpsand other elements.

[0008] In one aspect of the present invention, an air contaminantcontrol system for removal of carbon dioxide and other tracecontaminants from air comprises an absorber element for removal of aircontaminants and a stripper element to recondition liquid absorbent thatmay be used in the absorber element. The air to be processed flowsthrough the absorber element wherein liquid absorbent and an acid waterwash are mixed with the air in a two step process for direct contactcontaminant absorption and centrifugal removal of contaminants. The airflow is then passed through a charcoal bed filter and returned to theenvironment.

[0009] Another aspect of the present invention involves a method forremoval of carbon dioxide and trace contaminants from an air streamcomprising the steps of mixing the air stream with a liquid absorbentmist, separating the liquid absorbent from the air stream by centrifugalaction that deposits the liquid absorbent on a rotating heat and masstransfer plate removal of the liquid through use of pitot pumps, removalof droplets in a mist separator or labyrinth collector; passing the airflow through a cold acid water wash to further remove contaminants anddehumidify the air flow; separating the acid water wash from the airstream by centrifugal action that deposits the acid water wash on asecond heat and mass transfer plate, removal of the acid water washthrough use of pitot pumps, removal of droplets in a mist separator orlabyrinth collector; and passing the air flow through a charcoal bedfilter. Additional stages similar to those described here may be used toachieve a desired air purification condition.

[0010] Another aspect of the present invention involves the method ofliquid absorbent regeneration by thermal decomposition. The steps forthis process involve heating the carbonate rich liquid absorbent to thedecomposition temperature in a heater, spraying the heated liquid on toa rotating heat and mass transfer surface, separating the liquidabsorbent from the evolved carbon dioxide gas through centrifugalaction, removal of the carbonate lean liquid through the use of pitotpumps, and removal of droplets in a mist separator or labyrinthcollector. The product gas may be further purified in a second stage toremove water and absorbent vapors, which contaminate the carbon dioxide.The method is comprised of the steps of washing the product gas by aspray of cold absorbent liquid that is then sprayed onto a rotating massand heat transfer surface, separation of the liquid from the carbondioxide through centrifugal action, removal of the liquid through theuse of pitot pumps, and removal of droplets in a mist separator orlabyrinth collector. More stages similar to the ones described here maybe used to achieve the desired liquid absorbent regeneration and productcarbon dioxide purity.

[0011] These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdrawings, description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 illustrates a functional block diagram of the invention;

[0013]FIG. 2 illustrates a functional block diagram of the majorelements according to an embodiment of the invention;

[0014]FIG. 3 illustrates a functional cross-sectional view of a rotaryliquid contact processor apparatus according to an embodiment of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

[0015] The following detailed description is of the best currentlycontemplated modes of carrying out the invention. The description is notto be taken in a limiting sense, but is made merely for the purpose ofillustrating the general principles of the invention, since the scope ofthe invention is best defined by the appended claims.

[0016] Referring to FIGS. 1 and 2, an air contaminant control system 10has an absorber element 20 and a stripper element 80 in fluidcommunication and in control/data communication. Support elements suchas a control and data processor and an electric power source, not shown,are provided by existing platform equipment as is found on spacecraftand aircraft. The air contaminant control system 10 may be connected tothe cabin air system of a vehicle to process the return air from use ina vehicle human environment, to decontaminate and dehumidify the air,and to return cold clean air for use in a continuing cycle.

[0017] The current system absorber element 20 uses a rotary processscrubber 30 and charcoal bed filter 26 to remove contaminants. Bothliquid absorbent (such as an amine) and acid water are used in thescrubber 30 for direct contact liquid/vapor phase separation ofcontaminants. The stripper 80 may also use a rotary processor forliquid/vapor phase separation of liquid absorbent and carbon dioxide.The use of rotary processors allows operation in variable gravityenvironments such as experienced in aircraft and spacecraft and providescompact, light weight and reliable apparatus as compared to current artbulky, inefficient apparatus. In addition, the use of direct contactliquid/vapor processing allows more efficient heat transfer as comparedto current technology, which relies on use of condensing heatexchangers, slurpers, and rotating centrifugal phase separators. Acidwater spray may be used in the air contaminant control system to removeabsorbent vapor from the air and for temperature and humidity control.The acid water serves as an antimicrobial with the potential forreducing bacterial contamination or spread of pathogens.

[0018] Cabin air may be drawn through the scrubber 30 by a fan that maybe used to aid vehicle cabin ventilation air flow. In the scrubber 30carbon dioxide and other contaminates may be removed from the airthrough direct contact with a cool liquid absorbent. The liquidabsorbent removes carbon dioxide to form a carbonate complex. The termliquid absorbent as commonly understood in the art relates to carbondioxide liquid absorbents, as for example, water solutions of methanolamine, ethanol amine, isopropyl amine, cesium carbonate, magnesiumcarbonate and similar solutions. The choice of liquid absorbent may bebased on system operational factors such as carbon dioxide pressure,temperature, humidity, regeneration temperature and energy sources.

[0019] The amines have a low vapor pressure at absorption conditions;however, without treatment some amine vapor may remain in the processedair to be introduced into the vehicle cabin as a contaminate. To inhibitthis event an acid water scrubber 60 may be included in the scrubber 30to maintain amine pressure at acceptable levels, for example, about 1ppm. The same process may absorb other basic trace gases such asammonia. A mild acid, such as, citric, acetic, or hypo-phosphoric acid,may reduce the amine vapor pressure to the desired levels. The wateracid solution may become very diluted, but the pH should be maintainedrelatively low, i.e., greater than about 2 value. Additional acid may beadded to the acid water scrubber 60 to maintain a low pH. For a fullyclosed system acetic acid, vinegar, may be produced onboard a vehicleusing well known biological processes.

[0020] The carbon dioxide scrubber 40 may act to absorb acidic tracegases. The combination of the carbon dioxide scrubber 40 and acid waterscrubber 60 results in substantial removal of water soluble trace gases.There may also be hydrocarbon trace gasses in the air that may not beabsorbed in the scrubber 30. These gases may be removed by a charcoalbed filter 26 downstream of the scrubber 30. The charcoal bed filter 26may be a single use or regenerable device depending on the missionrequirements. Generally large portions of the trace contaminants areremoved in the scrubber 30 thereby reducing the contaminant load to beprocessed by the charcoal bed filter 26. Such action may allow for arelatively small charcoal bed filter 26.

[0021] The acid water wash sprayed into the acid water scrubber 60 mayact to control temperature and humidity by the use of a cold acid waterwash in the temperature range of about 40 to 60° F. The cooling occursdue to direct thermal contact when cool acid water is sprayed into theair flow. The large surface area of the spray that may be effective formass transfer may also be effective for heat transfer. Water vapor inthe air may condense in the cold acid water spray and then be separatedby the centrifugal action of the acid water scrubber 60 to adjust thehumidity. The resultant dilute acid water may then be accumulated inacid water tank 62. As part of the process water may be removed from theacid water tank and acid may be added to maintain proper pH for reuse inthe acid water scrubber 60. The removed dilute acid water may have saltsand dissolved trace gasses. It may be processed in a water recoverysystem in the host vehicle for reuse in the water cycle. Processed acidwater may be cooled at acid water cooler 64 and introduced to the acidwater scrubber 60.

[0022] The carbon dioxide rich liquid absorbent solution may also beprocessed for reuse in the carbon dioxide scrubber 40. The liquidabsorbent solution may be heated and processed through the stripperelement 80 to separate carbon dioxide from the liquid absorbentsolution. The carbonate complexes formed in the scrubber during theabsorption of carbon dioxide are thermally unstable, for example,methanol amine carbonate decomposes at 270° F. Approximately fivepercent of the flow of liquid absorbent used to treat the air in thescrubber 30 may be heated in liquid absorbent heater 44 and introducedinto the stripper 80. The stripper 80 may be a rotary contact processorsimilar to the rotary contact processor 32.

[0023] The stripper 80 permits evolution of the carbon dioxide and theseparation of the liquid phase. The method for the process using arotary contact processor comprises the steps of heating the carbonaterich liquid absorbent to its decomposition temperature in a flow throughliquid absorbent heater, communicating the heated liquid absorbent intoa first stage scrubber and spraying the heated liquid absorbent onto arotating heat and mass transfer surface thereby separating the liquidabsorbent from the evolved carbon dioxide gas through centrifugal actin,accumulating the carbonate liquid absorbent and removing it from thetransfer surface using pitot pumps, and passing the carbon dioxide gasthrough a plurality of mist separators for removal of droplets prior tobeing output.

[0024] The carbon dioxide gas may be further processed by introductioninto a second stage scrubber to remove water and absorbent vapors. Thecarbon dioxide gas may be washed by a spray of a cold liquid absorbentthat may then be sprayed onto a rotating mass and heat transfer surface,the liquid absorbent separation from the carbon dioxide may be caused bycentrifugal action, the liquid absorbent may then be accumulated andthen removed by pitot pumps, and the carbon dioxide may be passedthrough a plurality of mist separators for removal of droplets prior tobeing output.

[0025] In each case of the liquid absorbent and the carbon dioxideprocessing, more process stages may be used to obtain desired absorbentregeneration and product carbon dioxide purity.

[0026] The liquid absorbent may be first processed by a stripper element80 to remove carbonate complexes present in the solution. The heatedliquid absorbent may be sprayed into the stripper element 80, which maybe a rotary contact processor wherein the small droplets formed providea large surface area permitting efficient carbon dioxide transfer. Thepressure of the carbon dioxide may be controlled as for example by usinga back-pressure regulating valve. Depending on the liquid absorbentused, the pressure can be set in the range of 40 to 70 psi. The rotarystripper element 80 centrifugal action functions to separate the liquidand gas phases similar to the scrubber 30.

[0027] The resultant carbon dioxide vapor may be hot and contain watervapor and absorbent vapor. The vapors are removed in a stripper element80 by cooling the carbon dioxide and condensing the liquid. The coolliquid absorbent solution may be returned to the liquid absorbent tank42 and the carbon dioxide may be compressed, dried and stored forfurther use or disposal.

[0028] Referring to FIGS. 2 and 3, the scrubber 30 rotary contactprocessor 32 functions to provide direct liquid contact between air andtwo separate liquids, to separate the liquids and air, and to pump theliquids. The rotary contact processor 32 may be a dual rotor ambientpressure air scrubber that washes the air in the carbon dioxide scrubberrotor 104 with a carbon dioxide absorbant and washes the air with mildacid in the liquid absorbent scrubber rotor 107 as air flows through thedevice. It is supplied with a liquid absorbent solution, cooled acidwash water, atmospheric air, and electrical power. Electrical power isused for a drive motor, not shown. The advantage of this device is thatit operates at atmospheric pressure, it is gravity independent and itprovides a simple, rugged device.

[0029] The contact processor 32 consists of a rotor assembly comprisedof carbon dioxide scrubber rotor 104 and liquid absorbent scrubber rotor107 mounted in a housing 116 on bearings 120. Scrubbing and separationoccur within the rotor. Liquid absorbent solution may be circulatedthrough connections 102, 118 in the stationary hub 122 at one end andcooled acid wash water may be circulated through connections 105, 114 ina stationary baffle 115 located in the middle of the housing.

[0030] The two rotors 104, 107 are mounted on shaft 110 and areseparated by stationary baffle 115. The first rotor 104 is in the carbondioxide scrubber chamber 124 and may be used to remove carbon dioxidefrom the air stream. The second rotor 107 is in the acid wash scrubberchamber 126 and may be used to wash the air and to condense water fromthe air stream. Mist separators 111 and baffles 115 are used to isolatethe two fluids. The air may be moved through the rotary contactprocessor 32 by a built-in fan 112. An external blower, not shown, mayalso be used.

[0031] The rotary contact processor 32 operates in the following manner:atmospheric air flows in the inlet 101 past the carbon dioxide scrubberrotor 104, through air passage tubes 109 and mist separators 111, pastthe liquid absorbent scrubber rotor 107, through second air passagetubes 109 and second mist separators 111, and through the fan 112, tothe air exhaust 108. The fan 112 moves the air through the rotarycontact processor 32 and the drive motor, not shown, keeps the rotorsand fan moving at constant speed.

[0032] Carbon dioxide is removed from the air stream in the carbondioxide scrubber chamber 124. Liquid absorbent enters at connection 118and is sprayed into the air stream near the axis of rotation 128. Itforms droplets and a thin layer on the carbon dioxide scrubber rotor 104heat and mass transfer surface 117. The liquid flows by centrifugalaction to the outside of the carbon dioxide scrubber chamber 124. Thisdirect contact promotes the rapid absorption of carbon dioxide by theliquid absorbent. A mist separator 111 keeps liquid absorbent fromentering the next chamber. The liquid absorbent forms a layer on theperiphery of the chamber 124 and is pumped by the liquid absorbent pitotpump 103 through the liquid absorbent outlet 102 to an external liquidabsorbent tank 42. The return liquid absorbent enters through liquidabsorbent inlet 118.

[0033] The air is washed, cooled and humidity condensed in the acid washscrubber chamber 126. Cold acid wash enters through the acid water washinlet 114 and is sprayed into the air stream near the axis of rotation128. It forms droplets and a thin layer on the liquid absorbent scrubberrotor 107 transfer surface 117. The liquid flows by centrifugal actionto the outside of the acid wash scrubber chamber 126 and a portion ofthe humidity in the air stream condenses. The air stream is cooled belowthe dew point by the cold acid water wash. A mist separator 111 keepswater droplets from entering the exhaust stream at air exhaust 108. Thecondensate liquid forms a layer on the periphery of the chamber 126 andis pumped by the acid water pitot pump 106 through the acid water washoutlet 105 to the external circuit. The return cold acid water washenters through the acid water wash inlet 114.

[0034] While one embodiment is described in terms of a two stagescrubber 30 having a carbon dioxide scrubber 40 and a liquid absorbentscrubber 60 having a common rotor shaft and housing, these two elementsmay also be contained in separate housings with fluid communicationtherebetween. In such an instance, the baffle 115 would be separated instructure such that the carbon dioxide scrubber 40 would have an outletenclosed side and the liquid absorbent scrubber 60 would have an inletenclosed side. Also, more than two stages may be used depending on thepurity of the output desired by the user.

[0035] It should be understood, of course, that the foregoing relates topreferred embodiments of the invention and that modifications may bemade without departing from the spirit and scope of the invention as setforth in the following claims.

We claim:
 1. A contaminant control system for removal of carbon dioxideand other trace contaminants from air used for environmental controlcomprising: an absorber element in communication with a stripperelement, the combination communicable with a power source and a controland data processor; said absorber element having an air inlet incommunication with an air source, said inlet in communication with ascrubber; a charcoal bed filter in communication with said scrubber toreceive air flow output therefrom; said charcoal filter having an airoutlet in communication with said air source; a liquid absorbent tank incommunication with said absorber element, said stripper element and an aliquid absorbent heater; and an acid water tank in communication withsaid absorber element and an acid water cooler.
 2. The contaminantcontrol system as in claim 1 wherein said scrubber is comprised of arotary contact processor.
 3. The contaminant control system as in claim1 wherein said stripper element is comprised of a rotary contactprocessor.
 4. The contaminant control system as in claim 2 wherein saidscrubber is comprised of a carbon dioxide scrubber in fluidcommunication with a liquid absorbent scrubber.
 5. The contaminantcontrol system as in claim 2 wherein said rotary contact processorcomprises: a carbon dioxide scrubber rotor in serial communication witha liquid absorbent scrubber rotor connected by a rotor shaft rotatablyassembled on a plurality of bearings in a housing; said carbon dioxidescrubber rotor in communication with said air inlet and a liquidabsorbent inlet wherein a liquid absorbent is introduced as a mist intoan air flow through said air inlet, said air flow introduced into acarbon dioxide scrubber chamber having a first heat and mass transfersurface therein of said carbon dioxide scrubber rotor; said air flowpassing through said carbon dioxide scrubber rotor through a pluralityof first air passage tubes and a plurality of first mist separators tobe introduced downstream into an acid wash scrubber chamber separatedtherefrom by a baffle and having a second heat and mass transfer surfacetherein; said baffle having an acid water wash inlet for introduction ofa liquid acid water wash as a mist in said air flow; said air flowpassing through said liquid absorbent scrubber rotor through a pluralityof second air passage tubes and a plurality of second mist separators toa fan causing said air flow to exit said rotary contact processorthrough an air exhaust; a first pitot pump in said carbon dioxidescrubber chamber for liquid absorbent circulation and exit through an aliquid absorbent outlet; and a second pitot pump in said acid washscrubber chamber for liquid acid water circulation and exit through anacid water outlet.
 6. The contaminant control system as in claim 5wherein said liquid acid water wash is cold.
 7. A contaminant controlsystem for removal of carbon dioxide and other trace contaminants fromair used for environmental control in a vehicle comprising: an absorberelement rotary contact processor in communication with a stripperelement rotary contact processor, the combination communicable with apower source and a control and data processor; said absorber elementhaving an air inlet in communication with a vehicle air source, saidinlet in communication with a scrubber; a charcoal bed filter incommunication with said scrubber to receive air flow output therefrom;said charcoal filter having an air outlet in communication with saidvehicle air source; a liquid absorbent tank in communication with saidabsorber element, said stripper element and an a liquid absorbentheater; and an acid water tank in communication with said absorberelement and an acid water cooler.
 8. A rotary contact processor fordirect contact liquid absorbent and gas contaminant processingcomprising: a first scrubber rotor in serial communication with a secondscrubber rotor each assembled on a rotor shaft rotatably mounted on aplurality of bearings in a housing; said first scrubber rotor incommunication with a gas inlet and a liquid absorbent inlet wherein aliquid absorbent is introduced as a mist into a gas flow through saidgas inlet, said gas flow introduced into a first scrubber chamber havinga first heat and mass transfer surface therein of said first scrubberrotor; said gas flow passing through said first scrubber rotor through aplurality of first gas passage tubes and a plurality of first mistseparators to be introduced downstream into a second scrubber chamber influid communication therewith and having a second heat and mass transfersurface therein; said second scrubber chamber having a liquid absorbentwash inlet for introduction of a liquid absorbent wash as a mist in saidgas flow; said gas flow passing through said liquid absorbent scrubberrotor through a plurality of second gas passage tubes and a plurality ofsecond mist separators to a fan causing said gas flow to exit saidrotary contact processor through a gas exhaust; a first pitot pump insaid first scrubber chamber for liquid absorbent wash circulation andexit through a liquid absorbent outlet; and a second pitot pump in saidsecond scrubber chamber for liquid absorbent wash circulation and exitthrough a liquid absorbent water outlet.
 9. A rotary contact processorfor direct contact liquid absorbent air contaminant processingcomprising: a carbon dioxide scrubber rotor in serial communication withan liquid absorbent scrubber rotor connected by a rotor shaft rotatablyassembled on a plurality of bearings in a housing; said carbon dioxidescrubber rotor in communication with an air inlet and a liquid absorbentinlet wherein a liquid absorbent is introduced as a mist into an airflow through said air inlet, said air flow introduced into a carbondioxide scrubber chamber having a first heat and mass transfer surfacetherein of said carbon dioxide scrubber rotor; said air flow passingthrough said carbon dioxide scrubber rotor through a plurality of firstair passage tubes and a plurality of first mist separators to beintroduced downstream into an acid wash scrubber chamber separatedtherefrom by a baffle and having a second heat and mass transfer surfacetherein; said baffle having an acid water wash inlet for introduction ofa liquid acid water wash as a mist in said air flow; said air flowpassing through said liquid absorbent scrubber rotor through a pluralityof second air passage tubes and a plurality of second mist separators toa fan causing said air flow to exit said rotary contact processorthrough an air exhaust; a first pitot pump in said carbon dioxidescrubber chamber for liquid absorbent circulation and exit through aliquid absorbent outlet; and a second pitot pump in said acid washscrubber chamber for liquid acid water circulation and exit through anacid water outlet.
 10. The rotary contact processor as in claim 9wherein said liquid absorbent inlet and said liquid absorbent outlet arein communication with a liquid absorbent tank, a liquid absorbent heaterand a stripper element.
 11. The rotary contact processor as in claim 9wherein said acid water wash inlet and said acid water wash outlet arein communication with an acid water tank and an acid water cooler.
 12. Amethod for removal of carbon dioxide and other trace contaminants fromair used in environmental control, comprising the steps of: introducingan air flow into a carbon dioxide scrubber rotor and spraying a liquidabsorbent mist into said air flow; rotating said carbon dioxide scrubberrotor to separate said liquid absorbent containing absorbed carbondioxide and trace contaminants from said air flow; accumulating saidliquid absorbent on a first heat and mass transfer surface forextraction from said carbon dioxide scrubber rotor; passing said airflowdownstream of said carbon dioxide scrubber rotor through a plurality offirst air passages and a plurality of first mist separators to a liquidabsorbent scrubber rotor; spraying a liquid acid wash into said airflow; rotating said liquid absorbent scrubber rotor to separate saidliquid acid wash containing liquid absorbent, carbon dioxide and tracecontaminants from said air flow; accumulating said liquid acid wash on asecond heat and mass transfer surface for extraction from said liquidabsorbent scrubber rotor; and passing air flow downstream of said liquidabsorbent scrubber rotor through a fan to an air exhaust.
 13. The methodas in claim 12 wherein said extracted liquid absorbent is processed in astripper element for reuse.
 14. A method for reconditioning acontaminated liquid absorbent, comprising the steps of: heating a liquidabsorbent containing a carbonate to a decomposition temperature in aliquid absorbent heater; communicating said liquid absorbent into ascrubber; spraying said liquid absorbent onto a rotating heat and masstransfer surface for separation of said liquid absorbent from anabsorbed carbon dioxide; accumulating said liquid absorbent forextraction from said scrubber; and passing said carbon dioxide through aplurality of mist separators for output from said scrubber.
 15. Themethod as in claim 14 further comprising the steps of: communicatingsaid carbon dioxide into a second scrubber; washing said carbon dioxideusing a spray of a cold liquid absorbent; spraying said cold liquidabsorbent onto a rotating mass and heat transfer surface for separationof said cold liquid absorbent from said carbon dioxide; accumulatingsaid cold liquid absorbent for extraction from said second scrubber; andpassing said carbon dioxide through a plurality of mist separators foroutput from said second scrubber.
 16. The method as in claim 14 whereinsaid liquid absorbent is processed through a subsequent scrubber. 17.The method as in claim 15 wherein said cold liquid absorbent isprocessed through a subsequent scrubber.